Multi-Cannula Negative Pressure Irrigation System

ABSTRACT

This invention relates to a negative pressure irrigation system including one or more negative pressure irrigation needles sized for insertion into a canal of a tooth, each needle having a closed distal end and two suction inlet ports located opposite one another immediately proximal to the closed distal end. The needles are placed in communication with a dental vacuum system by way of a suction manifold. An irrigant inlet tube supplies irrigant from an irrigant container into a pulp chamber or a tooth. The irrigant inlet tube may include a tapered end designed to tightly fit into a lateral irrigant supply port previously drilled into the pulp chamber. A light-cure polymer seals the inlet tube and needles when in use.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application claiming priority to U.S.patent application Ser. No. 15/750,248, filed Feb. 5, 2018, which was anational phase filing of PCT Patent Application No. PCT/US2016/064978filed Dec. 5, 2016, which claimed priority to U.S. ProvisionalApplication No. 62/262,897 filed Dec. 3, 2015, all of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention is in the field of endodontic instruments and, morespecifically, negative pressure irrigation systems for use in cleaningroot canals.

Scientific research and clinical experience shows negative pressureirrigation (“NPI”) to be 1) one of the most effective methods ofcleaning or debriding root canals, 2) very inexpensive as it uses sodiumhypochlorite, the most inexpensive and most universally acceptedendodontic irrigating solution and the suction system found in everydental office, and 3) the safest method of applying the highly toxicsodium hypochlorite (NaOCl, common known as bleach) solution into rootcanals. Despite the exceptional efficacy shown by research and clinicalexperience, prior art NPI systems such as the EndoVac™ system (KerrEndodontics) include several design features that have severely limitedtheir use in clinical practice.

The first limiting feature is the needle, which includes 12 micro-portswithin the first 1 mm near the distal end (see e.g. FIG. 1). The portsfrequently clog as dental pulp fragments and cut dentin debris is suckedinto the ports during use. The EndoVac needle, for example, has a size0.32 mm external diameter, is a non-tapered needle with four sets ofthree laser-cut, laterally positioned offset holes are immediatelyproximal to its closed distal end (about the first 0.70 mm). Each holeof the set is 100μ in diameter (0.1 mm, smaller than the internaldiameter of the needle) and spaced 100μ apart.

The second limiting feature is the time required by the clinician whenusing the system in multi-canaled teeth because the clinician mustactively hold the NPI needle at the end of in a given canal as thesolution is evacuated down the root canals and out into the suctionsystem attached to the NPI needle. One positive aspect of PPI is that ithas a multi-cannular effect, meaning that in teeth with multiple canals,they are all cleaned simultaneously with PPI irrigation.

Current NPI systems are limited to a uni-cannular effect, meaning thatonly a single canal at a time can be actively cleaned with NPI. Becauseof this, prior art NPI systems actually increase the dentist's workloadin multi-cannular teeth. Currently, using NPI instead of PPI can reducethe time needed to complete cleaning of a root canal with NaOCl from 40minutes (PPI) to 5 minutes (NPI), however if NPI requires five minutesof constant NPI irrigation per canal, that necessity times four equalstwenty continuous minutes of attention required by the dentist ratherthan only ten minutes of the dentist's time spent actively irrigatingwith PPI.

The third limiting feature is that NPI currently requires constantattention by the clinician to repeatedly add NaOCl to the access cavityas the solution is drawn to the end of the canal and is evacuatedthrough the NPI needles. Whether the tooth being treated needs fiveminutes or 20 minutes of constant attention during NPI irrigation, it ismuch effort expended for a very simple need, replenishment of solution.

SUMMARY

The preferred embodiments of a multi-cannular negative pressureirrigation (“NPI”) system as disclosed here resolves all of the priorart limitations outlined above and offers the safest, least expensive,and most effective method currently known to endodontic treatment.

In a preferred embodiment, the NPI system includes one or more negativepressure irrigation needles each having a closed distal end and twosuction inlet ports located opposite one another immediately proximal tothe closed distal end. The ports may be triangular in shape and, becauseof their size, are the only ports required along the needle. Preferably,no other suction ports are proximal to these.

The needles are placed in communication with a dental vacuum system byway of a suction manifold. On one side of the suction manifold, there isa single tube arranged for connection to the dental vacuum system. Onanother side of the manifold, there are one or more needle tubes, eacharranged for connection to a corresponding negative pressure irrigationneedle.

An irrigant inlet tube supplies irrigant from an irrigant container intoa pulp chamber or a tooth. The irrigant inlet tube may include a taperedend designed to tightly fit into a lateral irrigant supply portpreviously drilled into the pulp chamber.

When in use the irrigant inlet tube is placed into the pulp chamber ofthe tooth and, along with the negative pressure irrigation needles whichare placed in a respective canal of the tooth, is sealed with alight-cure polymer at a cavo surface of an access cavity. This creates anegative pressure environment that draws irrigant from the irrigantcontainer through the irrigant inlet tube and into the pulp chamber,after which the irrigant is suctioned down a canal and is evacuated fromthe canal by the negative pressure irrigation needle, thus maintaining aclosed system vacuum.

The NPI needle's suction ports may be formed by cutting a slot into asquare-cut tip end of a needle material; bending a remaining sidewallportion of the needle material located on opposing sides of the slottoward one another so a respective tip end of each remaining sidewallportion contacts an opposing respective tip end; joining, welding, orbonding together the two tip ends when in contact with one another tocreate the closed distal end.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a prior art negative pressure irrigation (“NPI”) needle.

FIG. 2A is a preferred embodiment of a NPI needle prior to a first stepof its fabrication process.

FIG. 2B is the needle of FIG. 2A after a slot is cut into the tip end.

FIG. 2C is the needle of FIG. 2B after opposing ends of the slot arebrought together.

FIG. 2D is the needed of FIG. 2C after the ends are welded together,providing two inlet ports, one on each side of the needle, for suction.

FIG. 3A is a preferred embodiment of a NaOCl inlet tube and a singlesuction tube connected to a manifold.

FIG. 3B is a preferred embodiment of the manifold with two suctiontubes, each corresponding to a respective NIP needle.

FIG. 3C is a preferred embodiment of the manifold with three suctiontubes.

FIG. 3D is a preferred embodiment of the manifold with four suctiontubes.

FIG. 4 is an example of a preferred embodiment of the system used inconnection with a conventional access cavity cut into the pulp chamber.

FIG. 5 is another example of the system applied through the crown of amolar tooth that has been entered with a multiplicity of minimallyinvasive access holes, plus a lateral inlet port hole to feed the NaOClsolution into the pulp chamber.

ELEMENTS AND NUMBERING USED IN THE DRAWINGS AND DETAILED DESCRIPTION

-   -   10 Negative pressure irrigation system    -   20 Needle or cannula    -   21 Suction inlet port    -   23 Tip or distal end    -   25 Slot    -   27 Remaining sidewall adjacent slot    -   29 End of 27    -   30 Tubing system    -   31 Irrigant supply tubing    -   33 Irrigant container    -   35 Needle tubing    -   37 Suction manifold    -   39 Evacuator tubing    -   41 Irrigant inlet tube or cannula    -   43 Tapered end    -   45 Lateral irrigant supply port    -   49 Dental vacuum system    -   51 Light-cure polymer

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 2A-D, a preferred embodiment of a negative pressureirrigation (“NPI”) system 10 includes a NPI needle or cannula 20 withtwo suction inlet ports 21 at its tip end 23. The ports 21 arepreferably non-circular in shape. Unlike the prior art, the ports 21 arethe only ports within the first 1 mm from the tip end 23 and,preferably, are sized in a range of greater than 0.1 mm and less than aninternal diameter of the needle 20.

The inlet ports 21 of the needle 20 are preferably made by cutting aslot 25 in the tip end 23 of a needle material such as stainless steelor its equivalent; bending the remaining opposing sidewall portions 27until their respective ends 29 touch; and joining, welding, or bondingtogether the now-touching ends 29 together. This arrangement providesthe needle 20 with a maximum size of inlet ports 21 so the port 21, aswell as the needle 20, is less likely to clog with pulp remnants and cutdentin debris. The closed tip end 23 prevents periapical tissue fluidsfrom being suctioned up the needles instead of the intended irrigant(e.g. NaOCl) that is coursing down each of the canals alongside theneedle or needles 20 that evacuate the canals.

Referring to FIGS. 3A-D, NPI system 10 includes a tubing system 30reduced to just a single irrigant supply tubing or line 31 connected toan irrigant container 33, a NPI needle tubing 35 connected to the needle20 and to one side of a suction manifold 37, and a single evacuatortubing 39 connected on the other side of the suction manifold 37 and toa dental evacuation system 49. The irrigant supply line 31 may includean irrigant inlet tube 41 with a tapered end 43 designed to tightly fitinto a lateral irrigant supply port 45 previously drilled into a pulpchamber (see e.g. FIG. 4). The manifold 37 may have two or more NPIneedle tubes 35 each arranged for connection to a corresponding NPIneedle 20 for each canal in a given tooth.

The preferred embodiment of system 10 allows NPI needles 20 to be placedthrough the access cavity and to the end of each canal of a given tooth,along with an irrigant supply port 45 placed just into the pulp chamberof the tooth, after which a light-cure polymer 51 is syringed aroundthese needles 20 and the irrigant supply port 45 to seal the accesscavity so that all canals can be cleaned simultaneously, rendering thetime needed for NPI in a four canal molar tooth, for example, to dropfrom 40 minutes to 10 minutes in total, without additional time requiredby the treating clinician.

FIGS. 4 & 5 show two examples of system 10's application. The firstexample is in a tooth with a conventional access cavity cut into thepulp chamber. Each of the NPI needles 20 is inserted into the end pointsof the prepared canals, and an NaOCl inlet supply port 45 is placed, tofeed solution into the pulp chamber. Each cannula is sealed with a lightor chemically cured polymer 51 to create a closed system thatautomatically draws the NaOCl solution into the tooth through the vacuumdelivered by the NPI needles 20 in each canal.

The second example shows system 10 applied through the crown of a molartooth that has been entered with a multiplicity of minimally invasiveaccess holes, cut by micro-burs or laser, plus a lateral inlet supplyport 45 to feed the NaOCl solution into the pulp chamber alongside theNPI needles 20 in each canal. As in the first example, each of thesecannulas is sealed with a light or chemically cured polymer 49 that iseasily removed after irrigation has been completed.

What is claimed:
 1. An endodontic irrigation system (10) comprising: adental vacuum evacuator (49); two or more negative pressure irrigationneedles (20) each including a closed distal end (23) and two suctioninlet ports (21) located opposite one another immediately proximal tothe closed distal end; a suction manifold (37) including a tube (39) onone side connected to the dental vacuum evacuator and two or more tubes(35) on another side of the suction manifold each arranged forconnection to a corresponding one of the two or more negative pressureirrigation needles; an irrigant container (33); an irrigant inlet tube(41) connected to the irrigant container; and a light-cure polymer (51)first portion and second portion each portion spaced apart from thesuction manifold, the light-cure polymer portions in an unpolymerizedstate, the first portion directly contacting and sealably surrounding aportion of the two or more negative pressure irrigation needles and thesecond portion directly contacting and sealably surrounding a portion ofthe irrigant inlet tube, the portions being directly adjacent to aformed hole each configured to respectively receive the two or morenegative pressure irrigation needles and or the irrigant inlet tubebetween respective proximal and distal ends of the two or more negativepressure irrigation needles and of the irrigant inlet tube; the irrigantinlet tube forming a first irrigant passageway, one of the two or morenegative pressure irrigation needles and its corresponding one of thetwo or more tubes forming a second different irrigant passagewayindependent of the first irrigant passageway, and another of the two ormore negative pressure irrigation needles and its corresponding anotherone of the two of more tubes forming a third different irrigantpassageway independent of the first and second different irrigantpassageways; wherein when in an intended use the endodontic irrigationsystem draws irrigant from the irrigant container through the irrigantinlet tube and the irrigant is simultaneously suctioned down two or morecanals each containing a corresponding one of the two or more negativepressure irrigation needles; and wherein the irrigant is simultaneouslyevacuated from the two or more canals through the two or more negativepressure irrigation needles, thus maintaining a closed system vacuum. 2.An endodontic irrigation system according to claim 1 further comprisingthe irrigant inlet tube including a tapered end (43).
 3. An endodonticnegative pressure irrigation according to claim 1 further comprisingeach suction inlet port being triangular in shape.
 4. A negativepressure irrigation system according to claim 1 further comprising thetwo suction inlet ports being formed by: cutting a slot (25) into asquare-cut tip end of a needle material; bending a remaining sidewallportion (27) of the needle material located on opposing sides of theslot toward one another so a respective tip end (29) of each remainingsidewall portion contacts an opposing respective tip end; and joiningtogether the two tip ends when in contact with one another to create theclosed distal end.
 5. An endodontic irrigation system (10) comprising:two or more negative pressure irrigation needles (20) each including aclosed distal end (23) and two suction inlet ports (21) located oppositeone another immediately proximal to the closed distal end; a suctionmanifold (37) including a tube (39) on one side configured forconnection to a dental vacuum evacuator and two or more tubes (35) onanother side of the suction manifold each arranged for connection to acorresponding one of the two or more negative pressure irrigationneedles; an irrigant inlet tube (41) configured for connection to anirrigant container; and a light-cure polymer (51) first portion andsecond portion, each portion spaced apart from the suction manifold, thelight-cure polymer portions in an unpolymerized state, the first portiondirectly contacting and sealably surrounding a portion of the two ormore negative pressure irrigation needles and the second portiondirectly contacting and sealably surrounding a portion of the irrigantinlet tube, the portions each configured to respectively receive the twoor more negative pressure irrigation needles or the irrigant inlet tubebetween respective proximal and distal ends of the two or more negativepressure irrigation needles and of the irrigant inlet tube; the irrigantinlet tube forming a first irrigant passageway, one of the two or morenegative pressure irrigation needles and its corresponding one of thetwo or more tubes forming a second different irrigant passagewayindependent of the first irrigant passageway, and another of the two ormore negative pressure irrigation needles and its corresponding anotherone of the two of more tubes forming a third different irrigantpassageway independent of the first and second different irrigantpassageways; wherein when in an intended use the endodontic irrigationsystem draws irrigant from the irrigant container through the irrigantinlet tube and the irrigant is simultaneously suctioned down two or morecanals each containing a corresponding one of the two or more negativepressure irrigation needles; and wherein the irrigant is simultaneouslyevacuated from the two or more canals through the two or more negativepressure irrigation needles, thus maintaining a closed system vacuum. 6.An endodontic irrigation system according to claim 5 further comprisinga dental vacuum evacuator (49) and an irrigant container (33).
 7. Anendodontic irrigation system according to claim 5 further comprising theirrigant inlet tube including a tapered end (43).
 8. An endodonticnegative pressure irrigation according to claim 5 further comprisingeach suction inlet port being triangular in shape.
 9. A negativepressure irrigation system according to claim 5 further comprising thetwo suction inlet ports being formed by: cutting a slot (25) into asquare-cut tip end of a needle material; bending a remaining sidewallportion (27) of the needle material located on opposing sides of theslot toward one another so a respective tip end (29) of each remainingsidewall portion contacts an opposing respective tip end; and joiningtogether the two tip ends when in contact with one another to create theclosed distal end.